Explain trigger, Database Management System

Assignment Help:

What is Trigger?

A trigger is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE) occurs. Triggers are kept in and managed by the DBMS. Triggers are used to maintain the referential integrity of data by changing the data in a systematic fashion. A trigger cannot be called or implemented; DBMS automatically fires the trigger as a result of a data modification to the associated table. Triggers can be viewed as same to stored procedures in that both having of procedural logic that is kept at the database level. Stored procedures, though, are not event-drive and are not attached to a specific table as triggers are. Stored procedures are explicitly implemented by invoking a CALL to the procedure whereas triggers are implicitly executed. In addition, triggers can also execute stored procedures.

 


Related Discussions:- Explain trigger

Define the wait for graph, Define the Wait for graph Ans: The wait-for-...

Define the Wait for graph Ans: The wait-for-graph is a directed graph and consist of nodes and directed arcs; the nodes of the graph are active transactions. An arc of the grap

Relational schema, crete a data base relationship model Entity: ...

crete a data base relationship model Entity: Students; Professors; Dormitories buildings; Attributes of students: Name; Address; Dorm;

Short note on mid square method of hashing, Short Note on mid Square Method...

Short Note on mid Square Method of hashing? Mid square method of hashing: In the method midsquare hashing, the key is squared and the address selected from the center of the s

Copy data from one database to another database, Copy Data from One Databas...

Copy Data from One Database to another Database Project Description: I am having two MySQL databases with same tables. I just need to copy one Data from one to another dat

Define an abstraction, Define an abstraction by which relationships are tre...

Define an abstraction by which relationships are treated as higher level entities Ans: Aggregation.  It is an abstraction by which relationships are treated as higher level

Graphical user interface tools, These are interactive interfaces, graphical...

These are interactive interfaces, graphical that hide the difficulty of the DBMS and query language behind an intuitive, simple to understand, and convenient interface. This permit

Distributed and client server databases, Distributed And Client Server Data...

Distributed And Client Server Databases Introduction This unit tells the distributed database systems which are primarily relational and one important execution model: the

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

Explain b-tree, What is B-Tree? A B-tree eliminates the redundant stora...

What is B-Tree? A B-tree eliminates the redundant storage of search-key values .It permits search key values to appear only once.

Database errors, Database Errors: An error is said to have occurred if the ...

Database Errors: An error is said to have occurred if the implementation of a command to manipulate the database cannot be successfully finished either due to inconsistent data or

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd